A means is needed to dispose of light bulbs and lamps containing mercury or other conductive vapors in an environmentally sound manner. A fully environmentally sound disposition includes the proper disposal of the various components to which the light bulbs and lamps are ultimately reduced. To this end, it would be helpful if the crusher put those components in a condition to facilitate their further disposal while safely disposing of the potentially harmful heavy metal vapors.
Fluorescent light tubes are formed from elongated cylindrical or tubular glass enclosures which are sealed and then charged with mercury or other conductive vapors. The inside surface of the tube is coated with a fluorescent coating such as phosphorous or other phosphor powders. Mercury vapor is well known as a potentially toxic material.
Mercury containing bulbs are used for street lights and yard lamps. Such lamps are generally bulb shaped and have an inner glass envelope surrounding the light generating components. These lamps also contain mercury vapor and mercury in its liquid state. These lamps must be disposed of without permitting the entrained mercury from escaping to the environment.
A difficulty in reducing such bulbs and lamps is presented by the substantial non-glass content of such bulbs and lamps. This material has principally found in the end cap of the fluorescent tube and in the socket components of the mercury lamps. The materials included are principally plastic, aluminum, brass and lead wires.
In the past, systems designed to reduce fluorescent tubes have included devices for mechanically breaking the glass of the tube. U.S. Pat. No. 5,092,527 discloses a rotating two bladed paddle mounted within a relatively dose fitting housing for breaking fluorescent tubes inserted into the housing. U.S. Pat. No. 4,545,540 includes a device having a stationary set of blades and a interleaved rotary set of blades designed to break the glass of the fluorescent bulb. In such a device, the end caps are permitted to fall into the waste material without being affected by the rotating blade.
In the past, paired, counter rotating drums have been used to reduce input material. Such usages have been common in the mining industry and in the milling of grains and production of livestock feed. U.S. Pat. No. 4,046,324 discloses a solid waste shredder. The patent discloses a device having a fixed relationship between parallel shredding stacks. No provision is made for lateral motion to accommodate the passing of large, relatively incompressible solid waste through the device. U.S. Pat. No. 2,843,330 discloses a compliant geared drive train for use in maintaining a parallel relationship of paired crushing rolls when the rolls are laterally displaced. Similarly, U.S. Pat. No. 674,057 discloses crushing rolls having a wabbling drive system that permits a certain amount of lateral displacement of the rolls in the event that a relatively large piece of feed stock is being passed by the rolls.
None of the aforementioned past devices discloses or teaches the structure of the present invention.
As previously indicated, it is desirable to be able to dispose of the components to which the bulbs and lamps are reduced in an environmentally sound manner. There is a market for cleansed glass that has been reduced to small particles. Additionally, there is a market for aluminum as contained in the end caps, if the aluminum is separated from non-aluminum components, such as plastic and non-aluminum, and conducting wires. The plastics and conducting wires are frequently formed integral to the aluminum end caps of fluorescent light bulbs and present a challenge to separate such materials from the aluminum. In suitably reducing a fluorescent light bulb, it is important to simultaneously work the end cap sufficiently to cause the mechanical separation of the plastic and conducting wire components therefrom.
Accordingly, it would be a decided advantage in the industry to have a crusher suitable for use with fluorescent light bulbs and mercury vapor lamps that reduces the bulbs and lamps to small particles, but does not grind up the aluminum content, so that the aluminum is readily recoverable in a marketable state.